Squamous Cell Carcinoma In Situ

Squamous Cell Carcinoma In Situ: Treatment and Recurrence

Overview of Squamous Cell Carcinoma In Situ (SCCIS)

Squamous cell carcinoma in situ (SCCIS), also known as Bowen's disease, is a non-invasive form of squamous cell carcinoma that remains confined to the epidermis. It is considered a precursor to invasive squamous cell carcinoma (SCC) and requires timely treatment to prevent progression . SCCIS can develop due to factors such as prolonged sun exposure, fair skin, immunosuppression, and previous skin cancer diagnoses.

Treatment Modalities for SCCIS

Surgical Excision

Surgical excision is widely regarded as the gold standard for treating SCCIS due to its high efficacy and low recurrence rates. A retrospective study of 239 patients found that surgical excision had the lowest recurrence rate at 0.8%. This method involves removing the lesion along with a margin of healthy tissue to ensure complete removal.

Non-Surgical Treatments

Several non-surgical treatments are available for SCCIS, each with varying degrees of efficacy:

Cryotherapy: This method involves freezing the lesion with liquid nitrogen. It has a recurrence rate of 4.7%.
Photodynamic Therapy (PDT): PDT uses light-sensitive drugs and a light source to destroy cancer cells. However, it has a higher recurrence rate of 18% .
Topical Chemotherapy: Agents like 5-fluorouracil and imiquimod are applied directly to the lesion. These treatments have recurrence rates of 26.6% and 16.1%, respectively.
Electrodessication and Curettage: This method involves scraping away the lesion and using electric current to destroy any remaining cancer cells. It has a relatively low recurrence rate of 2.0%.

Emerging and Less Common Treatments

Other treatments such as laser ablation and radiation therapy are also used but are less common. These methods are often considered when other treatments are not suitable or have failed.

Factors Influencing Recurrence

Immunosuppression

Immunosuppression is a significant risk factor for the recurrence and progression of SCCIS. Patients who are immunosuppressed, such as organ transplant recipients, are more likely to develop aggressive forms of SCCIS and have higher recurrence rates .

Subclinical Lateral Extension

SCCIS often exhibits subclinical lateral extension, meaning the cancer cells spread beyond the visible lesion. This characteristic necessitates more extensive treatment, such as Mohs micrographic surgery, which involves removing the cancer layer by layer and examining each layer under a microscope until no cancer cells remain. Studies have shown that SCCIS requires more Mohs stages for complete removal compared to invasive SCC.

Other Risk Factors

Other potential risk factors for recurrence include tumor size, depth of follicular extension, and location of the lesion. However, more research is needed to quantify these variables and their impact on recurrence rates.

Conclusion

Squamous cell carcinoma in situ is a treatable condition with various surgical and non-surgical options available. Surgical excision remains the most effective treatment with the lowest recurrence rates. Non-surgical methods like cryotherapy, photodynamic therapy, and topical chemotherapy offer alternatives but generally have higher recurrence rates. Factors such as immunosuppression and subclinical lateral extension significantly influence recurrence and should be considered when choosing a treatment modality. Further research is needed to optimize treatment protocols and better understand the risk factors associated with SCCIS recurrence.

Summary

Not a yes or no question